I’m not sure about doing both of these sites in the same day, but Joseph (and I think Emma) made this trip a few times in the first few years of their marriage. Palmyra was a small town that benefited slightly from the construction of the Erie Canal and is the township where Joseph grew up from a young boy to a young man. He hobbled into Palmyra a little crippled boy still recovering from an intensive leg surgery and finally left as the leader of the Lord’s Restored Church.
It is uncertain whether or not the Smith Family lived in Palmyra or Manchester – if you look at the map in the Church new triples you’ll see that their property is right on the dividing line between the two townships – this is part of what leads to some confusion when Joseph references the town in his later recollections. There are many other uncertainties in studying Palmyra Church history.
While revival and camp meeting were common in the area a few years before 1820, there are no local references to them in the year 1820. This has led some historians, both faithful and otherwise, to suppose that Joseph Smith may have misremembered the exact year that his First Vision occurred, and that the First Vision possibly occurred earlier in 1818 or later in 1823 or 1824–right before the first visitation by the angel Moroni. Former BYU Historian D. Michael Quinn however has recently published a large study of the surrounding religious countryside in 1820 and has found good evidence that camp meetings, unmentioned by local newspapers and journals, occurred in the area in the late spring of 1820. Quinn has looked at the evidence (the local papers were not very good at reporting all sorts of local news, even missing a prominent death that occurred in Palmyra in 1820) and has come to a rather good argument that we can likely place the First Vision in the later weeks of June, 1820 (meaning that Joseph, writing later in warmer Missouri, remembered the warm weather when he went out and incorrectly deduced that the vision occurred in the “early” spring).
The other interesting and uncertain question has been “where is the Sacred Grove”? There’s not really any documentary evidence to show where it was located. The current site that is designated is a site that sits on the old Smith property and was never fully cleared for farming. Quinn speculates that possibly the land that the First Vision occurred in was forested at the time but was cut down as the Smith family expanded their farmland later, meaning it would currently be closer to the Smith Farmstead than the current site.
Also an interesting little tidbit about the Hill Cumorah and the Book of Mormon. In an interview with David Whitmer (one of the three witnesses; he never rejoined the Church) by the Chicago Times (August 1875), the paper gave this summary:
“David Whitmer was married in Seneca County, New York, in 1830, and was for a number of years an elder in the Church of Christ. Today he is the proprietor of a livery stable in Richmond, Missouri, owns some real estate, has a handsome balance in the bank, is universally respected by all who know him, and surrounded by children and grandchildren, is pleasantly gliding toward the gates of sunset, confident that the God of Abraham, Isaac and Jacob was also the God of Nephi, whose faithful disciple he has been and is… Three times he has been at the Hill Cumorah and seen the casket that contained the tablets and seerstone. Eventually the casket has been washed down to the foot of the hill, but it was to be seen when he last visited the historic place.”